From ejohansson@earthlink.net Fri Nov 22 22:59:33 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!earthlink!ejohansson From: ejohansson@earthlink.net (Emi Johansson) Newsgroups: comp.sys.m68k Subject: [SPECULATION] Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1996Nov22.225933.4206@earthlink.net> Date: Fri, 22 Nov 1996 22:59:33 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Tracing the address decoder lines on the motherboard reveals what was supposed to be in socket U14. Without U14, the board can track the 14.2 Hz carrier, but cannot descramble the binary payload of Nodes 11 through 14. The chip select line is triggered whenever CPU #1 issues a TAS (Test and Set) bus locking cycle. Did Marcus take the decryption EPROM with him when he left the lab? -- Emi Johansson *PLONK* filter active for trolls. Acorn RiscPC 600 - NetBSD 1.0 From jsato@inria.fr Sat Nov 23 11:31:33 1996 Path: ashpoly!cascade!transat!ukc!fennimore!inria!jsato From: jsato@inria.fr (Ji-woo Sato) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1996Nov23.113133.1175@inria.fr> Date: Sat, 23 Nov 1996 11:31:33 GMT References: <1996Nov22.225933.4206@earthlink.net> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996Nov22.225933.4206@earthlink.net>, ejohansson@earthlink.net (Emi Johansson) writes: > Tracing the address decoder lines on the motherboard reveals what was supposed to be in socket U14. > Without U14, the board can track the 14.2 Hz carrier, but cannot descramble the binary payload of Nodes 11 through 14. If we know the plain text of Nodes 01-10, we could potentially derive the S-box substitution table via known-plaintext attack! -- Ji-woo Sato "We don't sign stars. We build them." Amiga 1200 (Blizzard 030/50) / TOS 4.04 From hsato@uni-hamburg.de Sun Nov 24 16:32:33 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!uni-hamburg!hsato From: hsato@uni-hamburg.de (Hana Sato) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1996Nov24.163233.1775@uni-hamburg.de> Date: Sun, 24 Nov 1996 16:32:33 GMT References: <1996Nov22.225933.4206@earthlink.net> <1996Nov23.113133.1175@inria.fr> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1996Nov23.113133.1175@inria.fr>, jsato@inria.fr (Ji-woo Sato) writes: > If we know the plain text of Nodes 01-10, we could potentially derive the S-box substitution table via known-plaintext attack! Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984. -- Hana Sato -- Universität Hamburg Fachbereich Informatik "They will send a copy in my place."